Hearing devices that can be placed completely or almost completely in the ear canal are very popular, because they are suitable for most types of hearing losses and are relatively discreet. Some of these In-The-Ear (ITE) hearing devices can be placed deep in the ear canal. Invisible-In-The-Canal (IIC) hearing devices are located fully in and fit inside the ear.
In order to achieve a comfortable fit, an insert member (dome or tip) may be custom-made to the individual ear canal after taking a mould. Moreover, it is important to place the hearing device in the correct position in the ear canal in a way, in which the retention is good. It is also very important that the acoustic sealing is well defined, i.e. that the ventilation of the residual volume in front of the eardrum and behind the hearing instrument is well defined.
Optimum sealing properties (to the ear canal) may be accomplished by providing a custom-made insert member based on an ear canal impression/mould. Alternatively, it is possible to apply an instant approach in which silicone or foam is used for the sealing and where the size of the insert member (e.g. a silicon dome or a foam dome) is selected from a number of prefabricated fixed sizes.
Furthermore, comfortable insertion and safe fixation of an acoustically active part (end portion of a hearing aid tube through which the sound exits) of a bony seal hearing aid is crucial for customer acceptance. Prior art bony seal hearing aids comprise dome portions made of materials such as memory foam, silicon or alike to keep an acoustically active part in place while sealing the external ear canal. It has been observed that such materials, especially if worn on a long term basis, may cause skin irritations in the external ear canal of a user.
Accordingly, it would be useful to be able to form an insert member in an easier manner, in order to increase the comfort of the hearing device user and avoid making traditional ear canal impressions which are thrown away after usage. It may also be useful to provide a means which allows comfortable insertion and safe fixation of an acoustically active part of a hearing aid that is configured to be positioned in the bony part of the ear canal.